Syrian rebels have acquired advanced portable antiaircraft weapons that were smuggled into the war-torn country from Turkey and occasionally Lebanon. The missiles have been used to shoot down government helicopters and fighter jets, according to rebels and regional officials. “Northern Syria is awash with advanced antitank and antiaircraft weapons. The situation has changed very quickly,” a Syrian weapons coordinator said. The U.S. government is opposed to the weapons filtering into Syria because of fears they could end up in the hands of dangerous militia for use against Western countries. For rebel fighters, the new weapons could be the boost they need to fight against the more sophisticated state forces.